1. Field of the Invention
The present invention relates to electrical connectors and, particularly, to an electrical connector equipped with a ground terminal.
2. Description of the Related Art
Japanese patent application Kokai No. 10-255906 discloses an electrical connector of this type. This connector is shown in FIG. 14 for facilitating understanding.
In FIG. 14, a connector 60 has a ground pin terminal 61. The pin terminal 61 is made by machining a metallic material so as to provide a threaded section 62. A housing 63 has a receiving section 64 for receiving the threaded section 62. A ground terminal 65 is provided in the receiving section 64 and having a fixing flange 65A, a threaded tube 65B, and a connecting section 65C extending from the fixing flange 65A in an L-shaped form. Such a connector 60 is attached to a circuit board P1 and the connecting section 65C is connected to a corresponding section with a solder 66.
A mating connector 70 comprises a housing 71 having a ground terminal 72 that has a fixing flange 72A secured to the housing 71, a threaded tube 72B, and a connecting section 72C extending from the fixing flange 72A in an L-shaped form. A bush 73 has a threaded section 73A screwed into the threaded tube 72B, an intermediate section with a window 73B provided above the threaded section 73A, and an enlarged head section 73C above the intermediate section. The connector 70 is attached to a panel 74 by screwing the bush 73 into the ground terminal 72 so that the panel 74 is held between the housing 71 and the head section 73C. A hollow section is provided in the intermediate section and the head section 73C of the bush 73 for receiving the pin terminal 61. A U-shaped contact member 75 is provided on the bush 73 and has a contact section 75A slightly projecting from the window 73B into the hollow portion.
Similarly to the above connector 60, the connector 70 is attached to a circuit board P2 and the connecting section 72 is soldered to a corresponding section with a solder 76.
When the connector 60 is plugged into the connector 70, the pin terminal 61 enters the hollow portion of the bush 73 and makes contact with the contact section 75 and the threaded section 73A so that it is grounded through the ground terminal 72.
However, the above connector has several disadvantages about grounding.
First of all, the number of parts or components is very large. The connector 60 requires both the ground terminal 65 and the pin terminal 61 for grounding while the connector 70 needs the bush 73, the contact piece 75, and the ground terminal 72. The structures of these components are very complicated. The ground terminals 65 and 72 for the connectors 60 and 70 require threaded tubes 65B and 72B, respectively. The bush 73 for the connector 70 has the three stepped sections, the window section 73B, and the threaded section 73A below the head section 73C. The contact piece 75 requires complex press working so as to adapt for the pin terminal 61 of the connector 60.
Consequently, not only the manufacturing cost is high but also the connector becomes large. Also, the assembling becomes complex, and the electrical resistance can be high and the contact can be unstable. The pin terminal for contact with the ground terminal must be made of a metal material, which requires machining for providing the required shape and size, resulting in the increased cost.
Accordingly, it is an object of the invention to provide a compact electrical connector having simpler shape and structure and lower cost than ever before.
According to the invention there is provided an electrical connector equipped with a guiding column, which comprises a housing; at least one guiding column extending forwardly from the housing to be inserted into a guiding aperture of a mating connector; at least one ground terminal having a contact section for contact with a ground member of the mating connector; and a side recess provided in the guiding column to receive the ground terminal such that the contact section of the ground terminal projects from the side recess for making sliding contact with the ground member of the mating connector.
Since the ground terminal is provided within the guiding column, a compact connector is obtained. The ground terminal is made of a metal strip so that it is possible to reduce the manufacturing cost.
The guiding column may be made integrally with the housing as a unit and the ground terminal may have a connection section at the rear end so that the terminals are provided close to the guiding column, making the structure simpler and the connector smaller than before. The guiding column may be made of a metallic material and supported by the housing so as to make contact with the ground terminal and have a connection section at the rear end.
Where the shield case is attached to the housing, it is preferred that the ground terminal be made integrally with the shield case as a unit. Also, it is preferred that the guiding column be made of a metallic material so as to make contact with the shield case.
According to another aspect of the invention there is provided an electrical connector to be plugged with a connector equipped with a guiding column, which comprises a housing having an attaching face to be attached to a circuit board and a guiding aperture for receiving said guiding column; a ground member provided in said guiding aperture for sliding contact with a ground terminal of said guiding column-equipped connector; and an extended section extending from said ground member by a distance no greater than a thickness of said circuit board.
The guiding column is guided by the guiding aperture longer than before by a distance substantially equal to the thickness of the circuit board so that the contact between the ground member and the ground terminal of the mating connector is made more stable than before and the connector can be made compact by the presence of the extended section, which extends into the circuit board.